JPH04113173A - Hydrogen absorption heat pump - Google Patents

Abstract

PURPOSE:To avoid complex configuration and restrict a variation in a thermal transporting capability by a method wherein at least one of a heat absorption pipe and a heat radiation pipe is provided with a heat accumulator in series with the heat absorption heat exchanger or the heat radiation heat exchanger. CONSTITUTION:In the event that heat accumulators 9a and 9b are not present, a temperature of brine of low temperature supplied from either a hydrogen absorption heat exchanger 1 or 2 to a heat absorption heat exchanger 4 is high at an operation changing-over time region and becomes low temperature at a time period spaced apart from the changing-over time. A temperature of the brine supplied to the heat radiation heat exchanger 5 is made opposite. The heat accumulator 9a absorbs heat from the low temperature brine at a time changing-over time between a hydrogen absorption and discharging operation of a heat exchanger 1 or a heat exchanger 2 and then the heat is radiated to the low temperature brine at the time region spaced a part from the heat absorption time. Similarly, heat accumulator 9b releases heat to the brine of high temperature at a changing-over time of hydrogen absorption or releasing operation of the heat exchanger 1 or the heat exchanger 2 and absorbs heat from the brine of the high temperature at a time region spaced apart from it. With such an arrangement, a variation of brine temperature is restricted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hydrogen storage heat pump with little variation in heat transport capacity.

[Prior Art] JP-A-62-194164 discloses a pair of hydrogen storage heat exchangers that have a hydrogen storage alloy and exchange heat with air, and a compressor and a four-way valve that allows hydrogen to be transferred between the exchangers. Disclosed is a hydrogen storage heat pump type air conditioner comprising a hydrogen pressure-feeding pipe section that reciprocates hydrogen.

In this device, the heat exchanger repeatedly absorbs and radiates heat due to the hydrogen reciprocation, and as a result, one of the low-temperature air and high-temperature air coming out of the heat exchanger is supplied indoors, and the other is discharged into the atmosphere.

JP-A No. 62-294868 discloses a hydrogen storage heat pump in which two pairs of hydrogen storage heat exchangers each having a hydrogen storage alloy are provided, and each pair of hydrogen storage heat exchangers reciprocates hydrogen at different phases using a compressor. Disclose. In this device, thermal fluid is circulated between the two hydrogen storage heat exchangers on the hydrogen release side and the heat exchanger on the heat absorption side, and the thermal fluid is circulated between the two hydrogen storage heat exchangers on the hydrogen absorption side and the heat exchanger on the heat radiation side. Heat transport is carried out by circulating thermal fluid between the heat exchanger and the heat exchanger.

In this device, the heat transport peaks of the two pairs of hydrogen storage heat exchangers have a phase difference (time difference), so fluctuations in the overall heat transport waveform can be suppressed.

[Problems to be Solved by the Invention] However, the hydrogen storage heat pump having the above-mentioned pair of hydrogen storage heat exchangers has a low heat transport capacity, that is, heat absorption and heat dissipation capacity, due to the influence of the heat capacity of the hydrogen system, etc. every time hydrogen and air are switched. As a result, there is a problem that the heat transport capacity fluctuates greatly.

On the other hand, although the above-mentioned hydrogen storage heat pump with two pairs of hydrogen storage heat exchangers can reduce fluctuations in heat transport capacity, it requires additional hydrogen storage heat exchangers and the structure becomes more complicated, making it impractical. There is a problem of lack.

The present invention has been made in view of these problems, and an object to be solved is to provide a hydrogen storage heat pump that can suppress fluctuations in heat transport capacity while avoiding complication of the configuration as much as possible.

[Means for Solving the Problems] The hydrogen storage heat pump of the present invention includes a pair of hydrogen storage heat exchangers having a hydrogen storage alloy and a compressor, and a hydrogen storage heat pump that reciprocates hydrogen between the two hydrogen storage heat exchangers. A pressure feeding pipe section,
an endothermic piping section that circulates a thermal fluid between the endothermic side heat exchanger and the endothermic side heat exchanger, the hydrogen storage heat exchanger and the endothermic side heat exchanger on the hydrogen release side, and the hydrogen storage side on the hydrogen absorption side. a heat exchanger and a heat radiation piping section that circulates thermal fluid between the heat exchanger and the heat radiation side heat exchanger; The feature is that a heat storage device is installed in series with the

[Function] In the hydrogen storage heat pump of the present invention, the hydrogen pressure feed pipe section shuttles hydrogen between the pair of hydrogen storage heat exchangers by operating its compressor and switching the hydrogen flow path. A hydrogen storage heat exchanger that absorbs hydrogen radiates heat, and a hydrogen storage heat exchanger that releases hydrogen absorbs heat. The endothermic side heat exchanger absorbs heat from the object of heat absorption, and the endothermic piping section transports heat from the endothermic side heat exchanger to the hydrogen storage heat exchanger on the hydrogen release side. The heat radiation piping section transports heat from the hydrogen storage heat exchanger on the hydrogen absorption side to the heat radiation side heat exchanger, and the heat radiation side heat exchanger radiates heat to the heat radiation target.

In particular, the heat storage device, which is a feature of the present invention, is used at the peak of heat transport from the heat exchanger on the endothermic side to the hydrogen storage heat exchanger on the hydrogen release side (from the hydrogen storage heat exchanger on the hydrogen absorption side to the heat exchanger on the heat release side). At least one of cold heat and hot heat is absorbed from the thermal fluid at the peak of heat transport, and released when the direction of hydrogen flow is switched between the two hydrogen storage heat exchangers (at the bottom of heat transport).

[Example] (Example 1) An example of the hydrogen storage heat pump of the present invention will be described with reference to FIG.

This device has a pair of hydrogen storage heat exchangers 1.2 filled with hydrogen storage alloy.
Each has an airtight container (not shown) filled with powder of hydrogen storage alloy (MmN5) and equipped with a vent through which hydrogen gas can enter and exit.A pipe (not shown) through which brine flows is surrounding this airtight container. The hydrogen storage heat exchanger 1.2 is connected to the compressor 3 and a hydrogen pipe so that hydrogen can be reciprocated.

That is, the suction port of the compressor 3 and the hydrogen storage heat exchanger 1.2
and are individually connected via two-way valves 31, 32. Also, the discharge port of the compressor 30 and the hydrogen storage heat exchanger 1.
2 are individually connected via two-way valves 33, 34. The compressor 3, the two-way valves 31 to 34, and the hydrogen piping connecting them constitute a hydrogen pressure-feeding piping section in the present invention.

One end of each pipe wrapped around the hydrogen storage heat exchanger 1 described above is connected to the brine inlet of the heat absorption side heat exchanger 4 and the heat radiation side heat exchanger 5 through two-way valves 61 and 62, and The other end of the pipe is connected via a two-way valve 63.64 to the outlet of a brine circulation pump 7.8.

Similarly, one end of each pipe wrapped around the hydrogen storage heat exchanger 2 is connected to the brine inlet of the heat absorption side heat exchanger 4 and the heat radiation side heat exchanger 5 through three-way valves 65 and 66, and The other end of the pipe is connected via two-way valves 67, 68 to the outlet of a brine circulation pump 7.8.

The suction port of the brine circulation pump 7 is connected to the brine outlet of the heat absorption side heat exchanger 4' via the heat storage device 9a, and the suction port of the brine circulation pump 8 is connected to the heat radiation side heat exchanger 4' via the heat storage device 9b. It is connected to the brine outlet of No.5.

Here, the two-way valves 61, 63, 65, 67 and the brine piping between them and the endothermic side heat exchanger 4 constitute the endothermic piping section in the present invention, and similarly, the two-way valves 62, 64, . 66.
68 and the brine piping between them and the heat radiation side heat exchanger 5 constitute a heat radiation piping section in the present invention. In this case, the cooling mode is set, and the endothermic side heat exchanger 4 is on the indoor side,
The heat radiation side heat exchanger 5 is on the outdoor side, but during heating, by switching the two-way valves 61 to 68, the heat absorption side heat exchanger 4 on the indoor side can be easily used as the heat radiation side heat exchanger, and the heat exchanger on the outdoor side can be exchanged. Vessel 5
It is obvious that the can be operated as an endothermic heat exchanger.

Further, a temperature sensor 1b is provided in the brine pipe 1a connected to the brine outlet of the hydrogen storage heat exchanger 1, and a temperature sensor 2b is similarly provided in the brine pipe 2a connected to the brine outlet of the hydrogen storage heat exchanger 2. It is provided. The output signals V1 b of these temperature sensors 1b and 2b,
V2b is sent to the circuit shown in FIG. 2, and the two-way valves 61-68 are switched.

Note that the heat accumulators 9a and 9b are made up of tanks that store brine.

Next, the operation of this device will be explained.

First, we will explain hydrogen round trip. Initially, hydrogen is stored in the hydrogen storage heat exchanger 1, and the three-way valves 31 and 34 are opened.
Two-way valves 32,33 are in the closed state.

In such a state, when hydrogen gas is pumped from the hydrogen storage heat exchanger 1 to the hydrogen storage heat exchanger 2 by the operation of the compressor 3, the hydrogen storage heat exchanger 1, which releases hydrogen, absorbs heat from the brine and absorbs hydrogen. The hydrogen storage heat exchanger 2 radiates heat to the brine.

After the hydrogen storage heat exchanger 1 releases hydrogen gas for a predetermined period of time, the compressor 3 is stopped, the two-way valves 31 and 32 are opened, and the two-way valve 3 is opened.
3. If 34 is switched to the open state, hydrogen scum will flow from the hydrogen storage heat exchanger 2 to the hydrogen storage heat exchanger 1 because the hydrogen scum pressure in the hydrogen storage heat exchanger 2, which stores a large amount of hydrogen, is high. As a result, the hydrogen storage heat exchanger 2 absorbs heat from the brine, and the hydrogen storage heat exchanger 1, which absorbs hydrogen, radiates heat to the brine.

When the pressure difference in the hydrogen storage heat exchanger 1.2 falls below a certain level, the two-way valve 3L 34 is closed, and the two-way valve 32.33
is switched to the open state and the compressor 3 is operated. the result,
Hydrogen gas is continuously fed under pressure from the hydrogen storage heat exchanger 2 to the hydrogen storage heat exchanger 1. The hydrogen storage heat exchanger 2, which releases hydrogen, absorbs heat from the brine, and the hydrogen storage heat exchanger 1, which absorbs hydrogen, Heat is dissipated into the brine.

After the hydrogen storage heat exchanger 2 releases hydrogen gas for a predetermined period of time, the compressor 3 is stopped, the two-way valves 31 and 32 are opened again, and the three-way valves 33 and 34 are closed. Since the hydrogen gas pressure in the hydrogen storage heat exchanger 1 that stores
Hydrogen scum flows from the hydrogen storage heat exchanger 1 to the hydrogen storage heat exchanger 2, and as a result, the hydrogen storage heat exchanger 1 absorbs heat from the brine, and the hydrogen storage heat exchanger 2, which absorbs hydrogen, radiates heat to the brine.

In this way, by completing one round trip (one cycle) of the hydrogen gas or repeating this cycle thereafter, the brine coming out of the hydrogen storage heat exchanger 1 is heated and cooled at regular intervals. Due to the heat capacity of the hydrogen piping system, the temperature of the hydrogen storage heat exchanger 1.2 is as shown in FIG. 3(a), for example.

Next, the operations of the heat absorption piping section that always circulates cooling brine to the heat exchanger 4 on the heat absorption side and the heat radiation piping section that always circulates heating brine to the heat exchanger 5 on the heat radiation side will be described.

Temperature sensor 1b, 2b (7) output signal V 1 b,
V2b is sent to a comparator 100 shown in FIG. 2, and the comparator 100 goes low when Vlb is larger and goes high when V2b is larger.

Therefore, transistors 101-104 are turned on when V2b is larger, and conversely, transistors 106-109 are turned on when Vlb is larger due to the inversion of the output of inverter 105.

As a result, when the temperature of the hydrogen storage heat exchanger 2 is higher than the temperature of the hydrogen storage heat exchanger 1 (2b>Vlb), the two-way valves 61, 63, 66, 68, which are solenoid valves, respectively
opens and two-way valves 62, 64, 65, 67 close. Therefore, the pump 7 includes the hydrogen storage heat exchanger 1 and the heat absorption side heat exchanger 4.
, the low temperature brine is circulated through the heat storage device 9a, and the pump 8 circulates the high temperature brine through the hydrogen storage heat exchanger 2, the heat radiation side heat exchanger 5, and the heat storage device 9b.

Also, if the temperature of hydrogen storage heat exchanger 2 is
Two-way valve 61.63.66.68 when the temperature is lower than
closes and two-way valve 62,64,65,67 opens. Therefore, the pump 7 includes the hydrogen storage heat exchanger 2, the endothermic side heat exchanger 4,
The low temperature brine is circulated through the heat storage device 9a, and the pump 8 circulates the high temperature brine through the hydrogen storage heat exchanger 1, the heat radiation side heat exchanger 5, and the heat storage device 9b.

As a result, the heat exchanger 4 on the endothermic side is always supplied with low-temperature brine, and the heat exchanger 5 on the heat-radiating side is always supplied with high-temperature brine.

If there is no heat storage device 9a or 9b, the temperature of the low-temperature brine supplied from the hydrogen storage heat exchanger 1 or 2 to the endothermic side heat exchanger 4 as an indoor unit is
The temperature becomes high during the above-mentioned operation switching time period, and the temperature becomes low during the time period away from the switching time (Fig. 3 (b)
reference). Conversely, the temperature of the brine supplied from the hydrogen storage heat exchanger 1 or 2 to the heat radiation side heat exchanger 5 as an outdoor unit is between the hydrogen storage heat exchanger 1 or 2 between the hydrogen absorption operation and the hydrogen release operation. The temperature will be low during the time period switched by
The temperature becomes high in a time zone away from the switching time.

As a result, the cooling capacity of the endothermic side heat exchanger (indoor unit) 4 fluctuates significantly.

In this embodiment, since the heat storage units 9a and 9b are provided, the heat storage unit 9a absorbs heat from the low-temperature brine during the time period when the hydrogen storage heat exchanger 1 or 2 is switched between the hydrogen absorption operation and the hydrogen release operation. The heat is then radiated to the low-temperature brine during a time period away from the switching time. Similarly, heat storage device 9b
The hydrogen storage heat exchanger 1 or 2 radiates heat to the high temperature brine during the time period when it is switched between the hydrogen absorption operation and the hydrogen release operation, and absorbs heat from the high temperature brine during the time period away from the switching time.

As a result of the above, fluctuations in the brine temperature are suppressed, so the fluctuations in the cooling capacity of the endothermic side heat exchanger (indoor unit) 4 (i.e., the temperature of the low-temperature brine) are significantly reduced as shown in Figure 3 (C). reduced to

In this embodiment, the valves 61 to 68 are connected only to the temperature sensor 1b, regardless of the operation of the hydrogen storage heat exchanger 1.2.
, 2b, it has the advantage of being easy to control, as shown in FIG.

(Example 2) Another embodiment is shown in FIG.

This embodiment is different from the heat storage device 9b on the heat radiation side in the first embodiment.
is omitted to simplify the structure, and since the operation is the same, the explanation will be omitted.

Due to the omission of the heat storage device 9b, the temperature fluctuation of the heat radiation side heat exchanger 5 is large, but the fluctuation of the cooling capacity of the heat absorption side heat exchanger 4 as an indoor unit is significantly reduced as in the first embodiment.

(Example 3) Another example is shown in FIGS. 5 and 6. The hydrogen storage heat exchanger 1 absorbs hydrogen in FIG. 5 and releases hydrogen in FIG. 6.

This embodiment uses a bypass valve 400 and a four-way valve 401 instead of the two-way valves 31 to 34 in the second embodiment, and uses a four-way valve 402 instead of the two-way valves 61, 62, 65, 66,
A four-way valve 403 is used instead of the two-way valves 63, 64, 67, and 68.

By shutting off the bypass valve 400 and switching the four-way valve 401, it is possible for the compressor 3 to pump hydrogen in both directions, and by opening the bypass valve 400 and stopping the compressor 3, the flow between the two hydrogen storage heat exchangers is enabled. It will be seen that pressure equalization is possible.

Furthermore, by switching the four-way valves 402 and 403 in conjunction with each other, it is possible to constantly supply low-temperature brine to the heat-absorbing side heat exchanger (internal unit) 4 and constantly supply high-temperature brine to the heat-radiating side heat exchanger 5. can.

According to this embodiment, fluctuations in the cooling capacity of the heat exchanger 4 on the endothermic side can be suppressed with a simpler device configuration.

[Effects of the Invention] As explained above, the hydrogen storage heat pump of the present invention includes a heat storage device connected in series with at least one of the heat exchanger on the heat absorption side and the heat exchanger on the heat radiation side. -Because there are
At the peak of heat transport from the heat exchanger on the endothermic side to the hydrogen storage heat exchanger on the hydrogen release side (at the peak of heat transport from the hydrogen storage heat exchanger on the hydrogen absorption side to the heat exchanger on the heat release side), the heat storage device It absorbs cold or hot heat from the fluid and does not return to the thermal fluid when the hydrogen flow direction is switched between the two hydrogen storage heat exchangers (at the bottom of heat transport).

Therefore, according to the present invention, fluctuations in heat transport capacity can be suppressed with a simple device configuration.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the first embodiment of the present invention, Fig. 2 is a valve control circuit diagram, Fig. 3 is a waveform diagram showing changes in heat absorption amount, and Fig. 4 is a block diagram showing the second embodiment. , FIG. 5, and FIG. 6 are block diagrams showing the third embodiment. 1.2... Hydrogen storage heat exchanger 3... Compressor 4... Endothermic side heat exchanger 5... Heat radiation side heat exchanger 9a... Regenerator

Claims (1)

[Scope of Claims] A pair of hydrogen storage heat exchangers having a hydrogen storage alloy, a hydrogen pressure transmission pipe section having a built-in compressor and reciprocating hydrogen between the two hydrogen storage heat exchangers, and an endothermic side heat exchanger. and an endothermic piping section that circulates thermal fluid between the heat exchanger on the heat release side, the hydrogen storage heat exchanger on the hydrogen release side and the heat exchanger on the endothermic side, and the hydrogen storage heat exchanger on the hydrogen absorption side and the above. a heat radiation piping section that circulates thermal fluid between the heat radiation side heat exchangers, and a heat storage device in at least one of the heat absorption piping section and the heat radiation piping section in series with the heat absorption side heat exchanger or the heat radiation side heat exchanger. A hydrogen storage heat pump characterized by being equipped with.